1. Field of the Invention
The present invention relates to a post cure inflator for inflating and cooling a vulcanized tire by sealing high pressure air into the vulcanized tire.
2. Description of the Related Art
A reinforcing cord is embedded within a tire and, as the material of the reinforcing cord, there is used a chemical fiber material, e.g., polyester or nylon fiber. In manufacturing such a tire, if the tire after vulcanized is merely left to cool, the tire will be deformed due to a difference in the amount of contraction between rubber which constitutes the tire and the reinforcing cord. To prevent such a deformation, equipment called a post cure inflator has heretofore been used. According to this conventional equipment, high pressure air is sealed into a tire after vulcanized to maintain the tire in a proper shape and in this state the tire is cooled to a temperature (usually at 100° C. or below) at which the reinforcing cord ceases to contract.
The post cure inflator is provided with two annular rims for supporting bead portions of a tire in a sealed state. The rims are replaced according to the bead diameter of the tire to be treated. In the conventional post cure inflator, the rims are mounted to a body frame of the post cure inflator removably with bolts. When replacing the rims, therefore, it has been necessary to install and remove the bolts by a hand work. However, the rims are heavy (e.g., 10 kg or more per piece) and the footing of the working space for replacing rims is bad, therefore the operation for mounting and removing the rims with bolts to and from the body frame has imposed a heavy burden on the worker.
For facilitating the rim replacing work, for example Japanese Patent Laid-Open No. Hei 9 (1997)-70833 proposes a post cure inflator. This conventional post cure inflator includes upper and lower rims, rim mounting pieces fixed with bolts to surfaces on the side opposite to tire supporting surfaces of the upper and lower rims, two positioning guide pins provided on a body frame and extending in the vertical direction, and two rim mounting cylinders provided on the body frame. The rim mounting pieces are each formed with a hole extending therethrough radially of the rim. A rod of a rim mounting cylinder is fitted in the hole, whereby each rim mounting piece is secured to the body frame removably. Further, each rim is formed with a conical hole extending vertically through the rim, and a positioning guide pin is inserted into the conical hole.
When mounting each rim to the body frame, the rim and the associated rim mounting piece are fixed together integrally and the rim is positioned with respect to the body frame so that the positioning guide pin can be inserted into the conical hole of the rim. Thereafter, the rim and the rim mounting piece are put on the rim mounting surface, allowing the rim mounting cylinder to be fitted in the hole of the rim mounting piece. For removing the rim from the body frame there is performed a procedure reverse to the mounting procedure. By thus causing the rim and the rim mounting piece to raise and lower in the integrated state with respect to the body frame, the rim and the rim mounting piece can be mounted and removed to and from the body frame. Consequently, the mounting and removal of bolts become unnecessary and the replacement of rim can be done in a relatively easy manner.
However, in the case of the above-mentioned conventional post cure inflator, a conical hole for insertion therein of a positioning guide pin is formed in each rim to effect positioning at the time of mounting the rim to the body frame. Therefore, the existing rims used in the conventional post cure inflator cannot be used as they are and it is necessary to newly fabricate rims. Usually, a tire factory manufactures tires of various sizes and possesses a large number of rims different in rim diameter. For this reason it is desirable that existing rims be employable as they are.